40gbe DAC/fiber cables

[vitrag]

Hello All,

I have a wierd issue here.

Need to connect 2 switches (uplink) via 40G interface.
One side is an arista 7050QX and other side is a Dell S4048T-ON (alternate N4032 switch can be used). The issue i faced is as follows

- Mellenox Passive DAC cable (MC2210130)
-- loop connect between 2 dell ports, works fine (interface comes up)
-- loop connect between 2 arista ports, works fine (interface comes up)
-- connect between arista and dell, qsfp detected but no link

- DAC cable fron FS.com (coded with DELL on one side and Arista on other side)
-- loop connect between 2 dell ports, works fine (interface comes up)
-- loop connect between 2 arista ports, works fine (interface comes up)
-- connect between arista and dell, qsfp detected but no link
-- reverse connected between dell and arista (arista QSFP+ on dell side and Dell codec QSFP+ on arista side) the status is same QSFP+ detected but no link.

i have returend the FS.com cable as of now. However i am curious to understand what would cause such a behaviour.

Any thoughts /suggestions appreciated

 

[i386]

I've used an arista 7050q-16 with a brocade and mellanox switch and never experienced that behavior that you described...

-- connect between arista and dell, qsfp detected but no link

Did you use the same ports for all tests? Or did you try different ports on the switches?

 

[vitrag]

Yes tested Mellanox cables between Arista7050QX-32S --Brocade 6470T, seems to work there. the issue seems to be on Dell side, tested with 2 dell switches S4048T-ON and N4032; Arista -- Dell seems to be the problem

 

[vitrag]

Just had a call from the DAC supplier, he asked me to share some information from the switches, sharing here if it gives a better insight.